Part two: Ansible URI module and json_query filter

In my previous article I tried to explain how to use the Ansible URI Module and using the Jinja2 template engine to generate the JSON content. In part two I want to explain how to use the json_query filter. I will use the example with AVI Networks Load Balancers but this can be with any device with an REST API.

First we need to get the output from two objects, for both we don’t know the UUIDs and the first two tasks are to collect the configuration from the API using GET and register the output:

- block:
  - name: Avi | Get OpenShift cloud configuration
    uri:
      url: "https://{{ ansible_host }}/api/cloud/"
      method: GET
      user: "{{ avi_username }}"
      password: "{{ avi_password }}"
      return_content: yes
      force_basic_auth: yes
      validate_certs: false
      status_code: 200
      timeout: 180
      headers:
        X-Avi-Version: "{{ api_version }}"
    register: openshift_cloud 
   
  - name: Avi | Get OpenShift Service Engine group
    uri:
      url: "https://{{ ansible_host }}/api/serviceenginegroup/"
      method: GET
      user: "{{ avi_username }}"
      password: "{{ avi_password }}"
      return_content: yes
      force_basic_auth: yes
      validate_certs: false
      status_code: 200
      timeout: 180
      headers:
        X-Avi-Version: "{{ api_version }}"
    register: openshift_segroup
  when: '( inventory_hostname == groups["controller"][0] )'

The two variables openshift_cloud and openshift_segroup contain JSON content with all configuration details. For the OpenShift cloud object I don’t know the UUID, the only reference is the object name “OpenShift Cloud” which I know because I had previously created the object. I am using the Ansible module Set_Fact for specifying the query and writing the output into a new variable openshift_cloud_uuid:

- block:
  - name: Avi | set_fact for OpenShift cloud query
    set_fact:
      openshift_cloud_query: "[?name=='OpenShift Cloud'].uuid"
  
  - name: Avi | set_fact for OpenShift UUID
    set_fact:
      openshift_cloud_uuid: "{{ openshift_cloud.json.results | json_query(openshift_cloud_query) }}"
  when: '( inventory_hostname == groups["controller"][0] )' 

We now have the openshift_cloud_uuid of the OpenShift cloud configuration so let’s continue with the second object of the Service Engine group which is trickier because I don’t know the UUID or the object name. The Service Engine group was automatically set-up in the background when the OpenShift cloud object got created but I know the reference to the OpenShift cloud object and I use the json_query filter and set_fact again:

- block:
  - name: Avi | set_fact for Service Engine group query
    set_fact:
      openshift_segroup_query: "[?cloud_ref=='https://{{ ansible_host }}/api/cloud/{{ openshift_cloud_uuid[0] }}'].uuid"
  
  - name: Avi | set_fact for Service Engine group UUID
    set_fact:
      openshift_segroup_uuid: "{{ openshift_segroup.json.results | json_query(openshift_segroup_query) }}"
  when: '( inventory_hostname == groups["controller"][0] )'

Right now we know the openshift_cloud_uuid and the openshift_segroup_uuid, we use this to load a new Jinja2 template to update the Service Engine group object. See below the Jinja2 template openshift_segroup_json.j2:

{
  ...
  "name": "Default-Group",
  "tenant_ref": "https://{{ ansible_host }}/api/tenant/admin",
  "cloud_ref": "https://{{ ansible_host }}/api/cloud/{{ openshift_cloud_uuid[0] }}",
  ...
  YOUR CHANGES
  ...
}

The last part of this exercise is to load the j2 template and push the json content against the API to update the object using PUT:

- block:
  - name: Avi | set_fact to load Service Engine group json template
    set_fact:
      openshift_segroup_json: "{{ lookup('template', 'openshift_segroup_json.j2') }}"
  
  - name: Avi| Update OpenShift Service Engine group configuration
    uri:
      url: "https://{{ ansible_host }}/api/serviceenginegroup/{{ openshift_segroup_uuid[0] }}"
      method: PUT
      user: "{{ avi_username }}"
      password: "{{ avi_password }}"
      return_content: yes
      force_basic_auth: yes
      validate_certs: false
      body: "{{ openshift_segroup_json }}"
      body_format: json
      status_code: 200
      timeout: 180
      headers:
        X-Avi-Version: "{{ api_version }}"
  when: '( inventory_hostname == groups["controller"][0] )'

I hope this article is helpful on how to use the Ansible URI module and the json_query filter to extract information and update an API object. Please share your feedback and leave a comment.

Here you find the links to the other articles about Ansible URI module:

Part one: Ansible URI module and Jinja2 templating

This article about the Ansible URI module. I have recently spend a lot of time around automation for AVI software defined load balancers and wanted to share some useful information about how to use Ansible to interacting with REST API’s. Please check out my other articles around AVI Networks.

Let’s start with the playbook:

---
- hosts: controller
  gather_facts: false
  roles:
    - { role: "config" }

The config role needs the following folders:

config/
├── defaults    # Useful for default variables
├── tasks       # Includes Ansible tasks using the URI module
├── templates   # Jinja2 json templates
└── vars        # Variables to load json j2 templates

I will use defaults just as an example for variables which I use in the task and the json template.

Here’s the content of defaults/main.yml:

---
dns_servers:
  - 8.8.8.8
  - 8.8.4.4
dns_domain: domain.com
ntp_servers:
  - 0.uk.pool.ntp.org
  - 1.uk.pool.ntp.org
username: admin
password: demo
api_version: 17.2.11

Next the Json Jinja2 template, the example below is the system configuration from AVI load balancers but this can be any json content you want to push to a REST API, templates/systemconfiguration_json.j2:

{
  "dns_configuration": {
    {% if dns_domain is defined %}
    "search_domain": "{{ dns_domain }}"
    {% endif %}
    {% if dns_servers is defined %}
    {% for item in dns_servers %}
    "server_list": [
      {
         "type": "V4",
         "addr": "{{ item }}"
      }
      {% if not loop.last %}
      ,
      {% endif %}
      {% endfor %}
      {% endif %}
    ]
  },
  "ntp_configuration": {
    {% if ntp_servers is defined %}
    {% for item in ntp_servers %}
    "ntp_servers": [
      {
        "server": {
          "type": "DNS",
          "addr": "{{ item }}"
        }
      }
      {% if not loop.last %}
      ,
      {% endif %}
      {% endfor %}
      {% endif %}  
    ]
  },
  "portal_configuration": {
    "password_strength_check": true,
    "use_uuid_from_input": false,
    "redirect_to_https": true,
    "enable_clickjacking_protection": true,
    "enable_https": true,
    "disable_remote_cli_shell": false,
    "http_port": 80,
    "enable_http": true,
    "allow_basic_authentication": true,
  }
}

After we have specified the default variables and created the j2 template, let’s continue and see how we load the json template into a single variables in vars/main.yml:

---
systemconfiguration_json: "{{ lookup('template', 'systemconfiguration_json.j2') }}"

The step is the task itself using the Ansible URI module, tasks/main.yml:

---
- block:
  - name: Config | Systemconfiguration | Configure DNS, NTP and Portal settings
    uri:
      url: "https://{{ ansible_host }}/api/systemconfiguration"
      method: PUT
      user: "{{ username }}"
      password: "{{ password }}"
      return_content: yes
      body: "{{ systemconfiguration_json }}"
      force_basic_auth: yes
      validate_certs: false
      status_code: 200, 201
      timeout: 180
      headers:
        X-Avi-Version: "{{ api_version }}"
  when: '( inventory_hostname == group["controller"][0] )'

I like to use blocks in my Ansible tasks because you can group your tasks and use a single WHEN statement when you have multiple similar tasks.

I hope you find this article useful and please try it out and let me now in the comments below if you have questions.

Continue and read the other parts of this little series:

Here you find the links to the other articles about Ansible URI module:

Cisco IOS automation with Ansible

Bin a long time since I wrote my last post, I am pretty busy with work redesigning the data centres for my employer. Implementing as well an SDN Software-defined Network from VMware NSX but more about this later.

Ansible released some weeks ago new core modules which allows you to push directly configuration to Cisco IOS devices. More information you find here: https://docs.ansible.com/ansible/list_of_network_modules.html

I created a small automation lab in GNS3 to test the deployment of configs via Ansible to the two Cisco routers you see below. I am running VMware Fusion and used the vmnet2 (192.168.100.0/24) network for management because I run there my CentOS VM from where I deploy the configuration.

Don’t forget you need to pre-configure your Cisco router that you can connect via SSH to deploy the configuration.

Here the folder and file script structure of my Ansible example, under roles you have the different tasks I would like to execute common and logging but as well dependencies writecfg which saves the running-config to startup-config:

site.yml
hosts
group_vars/all.yml
roles/common/meta/main.yml
roles/common/task/main.yml
roles/common/templates/common.j2
roles/logging/meta/main.yml
roles/logging/tasks/main.yml
roles/logging/templates/common.j2
roles/writecfg/handlers/main.yml

The site.yml is the main script which I execute with Ansible which includes different roles for common and logging configuration:

- name: Cisco baseline configuration
  connection: local
  hosts: ios 
  gather_facts: false

  roles:
    - role: common
      tags: common
    - role: logging
      tags: logging

In the hosts file, I define the hostname and IP addresses of my IOS devices

[ios]
rtr01 device_ip=192.168.100.130
rtr02 device_ip=192.168.100.132

The file group_vars/all.yml defines variables which I used when the script is executed:

---
username: "ansible"
password: "cisco"
secret: "cisco"
logserver: 192.168.100.131

Under the roles/../meta/main.yml I set a dependency on the writecfg handler to save the configuration later when I change anything on the device.

Under the roles/../tasks/main.yml I define the module which I want to execute and the template I would like to deploy

Under the roles/../templates/.. you find the Jinja2 template files which include the commands.

Under roles/writecfg/handler/main.yml is the dependencies I have with the two roles common and logging to save the configuration if something is changed on the router.

To execute the cisco-baseline Ansible script just execute the following command and see the result:

[[email protected] cisco-baseline]$ ansible-playbook site.yml -i hosts

PLAY [Ensure basic configuration of switches] **********************************

TASK [common : ensure common configuration exists] *****************************
ok: [rtr02]
ok: [rtr01]

TASK [logging : ensure logging configuration exists] ***************************
changed: [rtr02]
changed: [rtr01]

RUNNING HANDLER [writecfg : write config] **************************************
ok: [rtr01]
ok: [rtr02]

PLAY RECAP *********************************************************************
rtr01                      : ok=3    changed=1    unreachable=0    failed=0
rtr02                      : ok=3    changed=1    unreachable=0    failed=0

[[email protected] cisco-baseline]$

Read my new posts about Ansible Playbook for Cisco ASAv Firewall Topology or Ansible Playbook for Cisco BGP Routing Topology.